Project files: Regulated PSUs – part 2

What is it?These are variable-voltage regulated power supplies based on LM317/LM337(-type) regulators. These are useable for a wide variety of applications. You can use normal LM317-regulators or substitute higher-current LM350/LM338 or low-dropout LM/LD/LT108x types as the boards only use positive regulators. There are two basic versions, one version using small heat sinks (Fischer SK104-style) and one using larger heat sinks (Fischer SK129-style). Both boards are available in single and dual versions.

How big are the boards?Small boards:
– single version 3.6×1.175″ (app. 91x30mm)
– dual version 3.6×2.25″ (app. 91x57mm)
Large boards
– single version 3.925×1.75″ (app. 100x44mm)
– dual version 3.925×3.5″ (app. 100x89mm)

What is the status of the boards?These boards are in version 1.0. I have built and tested both dual versions and they work well. The single versions are exactly identical and should work perfectly also.

Does it use any special/expensive/hard-to-find parts?No, all these parts are reasonably standard.

Anything else I need to know?

The heat sinks on these boards are not that big, so remember to watch the power dissipation – especially if the regulator needs to drop a large voltage.

These designs assume you are at least somewhat familiar with how the LM317-type voltage regulators function and operate.

Always check the manufacturer’s datasheet for the regulators of your choice to confirm all component values and load conditions. This is especially important if you decide to use low-dropout (LDO) or low-noise types that could have slightly different parameters.

Downloads:Download design files here (large boards)Download design files here (small boards)For a small spreadsheet that can be used to calculate resistor values, output voltages etc. for the regulators, see the “download” page (or google to find an online calculator)